hemicellulose‐bound form of silicon with potential to improve the mechanical properties and regeneration of the cell wall of rice

• Published in: The New phytologist Vol. 206; no. 3; pp. 1051 - 1062
• Main Authors: He, Congwu, Ma, Jie, Wang, Lijun
• Format: Journal Article
• Language: English
• Published: England Academic Press 01.05.2015; New Phytologist Trust; Wiley Subscription Services, Inc
• Subjects: Analytical methods; atomic absorption spectrometry; Atomic force microscopy; Cell Fractionation; cell wall; Cell Wall - chemistry; Cell Wall - metabolism; Cell Wall - physiology; cell wall regeneration; Cell walls; Cellulose; confocal laser scanning microscopy; Confocal microscopy; Hemicellulose; hemicellulose‐bound form of Si; Inductively coupled plasma mass spectrometry; Lasers; Ligands; Mass Spectrometry; Mass spectroscopy; Mechanical properties; mechanical property; Microscopy; Microscopy, Atomic Force; Oryza - chemistry; Oryza sativa; Pectin; pectins; Photoelectron Spectroscopy; Photoelectrons; Polysaccharides - analysis; Polysaccharides - chemistry; Protoplasts - chemistry; Regeneration; Regeneration (biological); rice; Scanning microscopy; Silicon; silicon (Si); Silicon - analysis; Silicon - chemistry; X-ray photoelectron spectroscopy; Oryza sativa; hemicellulose; cell wall regeneration; hemicellulose-bound form of Si; silicon (Si); mechanical property; cell wall
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/nph.13282

Silicon (Si) plays a large number of diverse roles in plants, but the structural and chemical mechanisms operating at the single‐cell level remain unclear. We isolate the cell walls from suspension‐cultured individual cells of rice (Oryza sativa) and fractionate them into three main fractions including cellulose (C), hemicellulose (HC) and pectin (P). We find that most of the Si is in HC as determined by inductively coupled plasma‐mass spectrometry (ICP‐MS), where Si may covalently crosslink the HC polysacchrides confirmed by X‐ray photoelectron spectroscopy (XPS). The HC‐bound form of Si could improve both the mechanical property and regeneration of the cell walls investigated by a combination of atomic force microscopy (AFM) and confocal laser scanning microscopy (CLSM). This study provides further evidence that HC could be the major ligand bound to Si, which broadens our understanding of the chemical nature of ‘anomalous’ Si in plant cell walls.